Linn Maung
China, home to some of the world’s largest cities, is grappling with a grave environmental crisis. An alarming 82 of its cities are sinking, a phenomenon that threatens to disrupt the lives of millions of people, the economy, and the environment.
Rapid urbanization and excessive groundwater extraction have led to land subsidence, causing the ground to sink. This is not just a geological issue; it’s a socio-economic problem of enormous proportions. Millions of people are at risk as their homes and workplaces become increasingly unstable. Infrastructure damage from sinking land is escalating, leading to significant economic losses.
The environmental impact is equally concerning. Land subsidence can lead to increased flood risks and damage to ecosystems. It exacerbates the effects of sea-level rise in coastal cities, posing a significant threat to China’s already vulnerable coastal regions.
The Chinese government has implemented measures to curb groundwater extraction and promote sustainable urban planning. However, the scale of the problem necessitates more comprehensive and long-term solutions.
This crisis serves as a stark reminder of the consequences of rapid urban development without adequate environmental safeguards. It underscores the urgent need for sustainable practices in urban planning and water management, not just in China, but globally. The sinking cities of China are a wake-up call to the world about the human and environmental costs of unchecked urbanization.
China is wrestling with a formidable challenge. The land beneath the feet of its citizens is sinking, with over half of its major urban centers under threat. This land subsidence issue could cast a shadow over the lives of more than 100 million individuals in the coming hundred years. The scientific community is sounding the alarm bells, warning of the impending repercussions. Scientists from the University of East Anglia and Virginia Tech have conducted a study that underscores the peril faced by almost half of China’s 82 major cities due to swift land subsidence. Their research, published in “Science,” indicates that this alarming phenomenon could potentially impact a population ranging from 55 to 128 million by the year 2120, unless preventive measures are promptly implemented.
Despite posing a substantial risk, the problem of land subsidence in Chinese urban areas has largely been overlooked and downplayed. The investigators emphasize that land subsidence is a pervasive occurrence with potential for severe consequences. This phenomenon could put as much as 19% of the world’s population in jeopardy. The main triggers of subsidence encompass both natural elements and human activities, with the utilization of groundwater for human needs being a significant contributor.
In order to measure the magnitude of the issue, the research group scrutinized satellite data pertaining to land subsidence throughout China, with a spotlight on 82 cities that are home to close to 700 million individuals. Their examination disclosed that 45% of these metropolitan regions are experiencing a downward shift, influencing the lives of 270 million inhabitants. Furthermore, in about 16% of these regions, the land is descending at a pace of 0.4 inches annually or even faster, impacting roughly 70 million citizens, with Beijing and Tianjin confronting the gravest circumstances.
Coastal metropolises, Tianjin being a case in point, are particularly susceptible to the perils of subsidence, a situation exacerbated by the escalating sea levels attributable to climate change. This amalgamation of elements has already manifested catastrophic repercussions, as evidenced in New Orleans during the onslaught of Hurricane Katrina in 2005. The event precipitated extensive flooding and stands as one of the most monumental natural calamities in the annals of the United States.
In Beijing, the tremors triggered by vehicular movement and tunnel excavation are hastening the process of land subsidence. Regions in proximity to subway routes and major roads are witnessing a descent rate of approximately 1.8 inches annually. Shanghai, the most populous city in China, has also undergone a significant decrease in ground elevation—around 10 feet in the past hundred years—and this trend doesn’t seem to be decelerating.
Specialists caution that if the present rate of land subsidence and sea-level elevation persists, the portion of Chinese urban territories below sea level could potentially triple by the year 2120. This scenario could endanger a population ranging from 55 to 128 million individuals. Absent immediate intervention from the governing bodies, the consequences could be calamitous.
“Land subsidence poses a risk to structures and vital infrastructure, and it intensifies the effects of climate change, such as flooding. This is particularly true in coastal regions that are susceptible to rising sea levels,” states Professor Robert Nicholls from the University of East Anglia.
However, there is a silver lining, as demonstrated by the cases of Osaka and Tokyo. Alterations in the policies governing groundwater usage in the 1970s resulted in a substantial decrease or even a cessation in subsidence. The investigators contend that the task of tackling land subsidence extends beyond the confines of Chinese urban areas and is a matter of global importance. It necessitates a unified endeavor from the scientific fraternity and city planners to discover and put into action effective solutions.
